Pump piston



De.1.4-,1943.- P A T 2,336,803

PUMP PISTON Filed May 5, 1942 3 Jesse M. Pfafl INVENTOR' A TTORNEYS Fatented Dec. 14, 1943 PUMP PISTON Jesse M. Pratt, Houston, Tex., assignor to Howard F. Smith, Sr., Houston, Tex.

Application May 5, 1942, Serial No. 441,778

Claims.

This invention relates to pumping apparatus and more particularly has reference to the construction of pistons for deep well pumps.

In deep well pumps especially those employed for pumping oil from wells of considerable depth it is desirable to provide a piston construction which will withstand considerable wear and which will not have to be removed for adjustment and repairs at frequent intervals. The cost of removing and replacing a piston in a deep Well of the type above referred to is considerable because of the time involved in removing and replacing the same and because of the losses incurred due to the non-production of the well in its period of inactivity.

Pistons for use in deep well pumps are usually provided with sealing or packing rings or cups of leather or the like but there are disadvantages in employing such type of rings which are not inherent in metal rings. At present, however, there are no pistons of the type referred to having metal packing rings thereon which have proven successful.

An object of this invention is to provide a piston for deep well pumps which will avoid the disadvantages of the prior art as pointed out above.

Another object of this invention is to provide a piston for deep well pumps which is fitted with a plurality of metal piston rings.

A further object of this invention is to provide a piston for deep well pumps which comprises a tubular body having a plurality of metal piston rings mounted thereon and a plurality of annular spacing elements positioned between said piston rings,

Yet another object of this invention is to provide a piston for deep well pumps which comprises a tubular body having a plurality of metal piston rings thereon and means operable upon reciprocation of the piston for imparting rotation to the piston rings.

Still another object of this invention is to provide a piston for deep well pumps which comprises a tubular body having a plurality of metal piston rings thereon, each piston ring being formed of a plurality of segmental parts, and means for loosely retaining said segmental par-ts assembled together.

A still further object of this invention is to provide a piston for deep well pumps which comprises a tubular body having a plurality of metal piston rings thereon, each piston ring being formed of a plurality of segmental parts, means for loosely retaining said segmental parts assembled together, and in which means are provided for resiliently urgingv said segmental parts radially outwardly.

With these and other objects in view the invention resides in the parts and combinations hereinafter described and illustrated in the accompanying drawing.

In the drawing:

Figure 1 is an elevational View partly in section of a deep well pump piston constructed in accordance with the present invention.

Fig. 2 is a transverse sectional view taken on line 2-2 of Fig. 1.

A piston for deep well pumps constructed in accordance with the present invention comprises a tubular body I which is elongated axially. Said tubular body is provided with an enlarged head 2 at the lower end thereof which serves as an abutment for rotatable elements mounted on" the tubular body as will be hereinafter described. At its upper end the tubular body I is externally threaded and has a fitting 3 mounted thereon. Fitting 3 comprises a lower internally threaded portion which receives the upper threaded end of the tubular body l and is provided with an upper externally threaded portion which cooperates with the lower internally threaded portion of a cap 4 which serves as a valve cage. The upper end 5 of the cap 4 is of reduced cross sec tion and is externally threaded to receive the lower end of the pump rod which serves to reciprocate the piston.

As will be observed from the structure shown in Fig. 1, the cap 4 is provided with a plurality of openings 6 in the upper portion thereof and. is formed with an internal shoulder 'l' which lies above the upper end of the fitting 3 when the cap 4 is mounted on the latter. Shoulder "I and the upper end face of the fitting 3 are recessed to receive a circumferential flange 8 of an annular valve seat member 9 mounted within the cooperating bores of the fitting 3 and the cap 4. A valve body in the form of a ball ill is mounted within the cage formed within the upper portion of the cap 4 and is adapted to seat onthe annular Valve seat member '9 to close the bore extending through the tubular body i during upward movement of the latter through the pump cylinder.

On the upper threaded portion of the tubular body I there is mounted a detachable abutment or nut i l and on the lower portion of the tubular body I there is loosely rotatably mounted an annular member i2 provided with grooves i3 inclined relatively to the axis of the piston as illustrated in Fig. 1 of'the drawing. Axially spaced between the adjustable abutment ii and the annular member I2 are a plurality of spac- Each piston ring is formed of three or any other desirable. number of segments or elements as illustrated in Fig. 2 of the drawing. The ends of the three segments of the piston ringsare.

stepped as shown in Fig. 1 to provide-a seal between the joined segments. By making the piston rings of a plurality of segmental parts the rings are more readily outwardly expandable into engagement with the pump cylinder. For expanding the segments of the ring I5 outwardly resilient expanders I6 are provided which arev mounted in annular grooves in the inner'surfaces of the piston rings I5 as shown in Fig. 1.

Each piston ring is provided with upwardly and downwardly extendingflanges I1 and I8 at the ends thereof adjacent the inner periphery thereof. The upper end of the annular member I2 is recessed or otherwise formed to provide an upstanding or axially extending flange I9 adja-- cent the outer peripheral portion thereof. Flange I9 overlaps and cooperates with the lower flange I8 on the piston ring I5 adjacent the annular member I2 to retain the segments of said piston ring assembled about the tubular body of the piston I. At the upper end of the piston the nut or abutment II is provided with a down wardly axially extending flange 20 adjacent the outer peripheral portion thereof which overlaps and cooperates with the upper flange I! on the piston ring I5 in engagement with the nut II to retain the segments of said piston ring assembled about thebody of the piston I. c

The spacing rings I4 are. provided with upper and lower axially extending flanges 2| and 22 which overlap and cooperate respectively with the lower flanges I8 and the upper flanges ll of piston rings mounted above and below said spacing rings.

With the provision of the flanges I! and I8 on the piston rings and the overlapping and cooperating flanges I9, 20, 2| and 22 on the annular member I 2, the abutment II and the-spacing rings I4 respectively, the piston rings are effectively retained in assembled position about the body of piston I against outward or radial movement urged by the resilient expanders I6.

The plurality of piston rings mounted on the piston I for outward expansion as described above will effectively seal the piston within the pump cylinder. To maintain even wear on the piston rings and insure an effective seal over long periods of time, the present invention provides for theperiodic rotation of the piston rings through a slight degree about the body of the piston I during reciprocation of the later within the pump cylinder. For this purpose the annularmember I 2 is provided with the aforementioned inclined grooves I3;

Annular member l2 as well as the spacing rings, I4 and the piston rings I5 are mounted on the piston body suificiently loosely so that they may rotate on the body. Also there is sufficient frictional engagement between the annular member I2, the rings I5 and the spacers I 4 to transmit motion from member I2 to the rings I5 and spacers I4.

At the instant that the piston reaches the upper end of its stroke and starts downwardly, there will be a slight flow of fluid upwardly past the annular member I2 and this fiow will act upon the grooves i3 therein and cause a slight rotation of this ring. This rotation though very slight will be transmitted to the adjacent piston. ring I5 and in turn through the following series of spacing rings I4 and piston rings I5 to effect a slight rotation of all of the piston rings. With this action the piston rings will therefore not "remain in one position but will be kept rotating slightly during each stroke of the piston.

This

rotation is extremely slight but any rotation whatever is suificient to accomplish the purpose so long as it takes place during each stroke of the-piston.

From the foregoing description, it will be appreciated that the present invention provides a piston construction on which metal piston rings are assembled for accomplishing and maintaining an effective seal between the piston and the pump cylinder over long periods of time.

Having described my invention, I claim:

. l. A piston for deep well pumps comprising a tubularbody having a plurality of metal piston rings freely rotatably surrounding the same, and a plurality of freely rotatable spacing rings interposed between adjacent piston rings.

. 2. A piston for deep well pumps comprising a tubular .body having a plurality of metal piston rings surrounding the same, each piston ring being formed of a plurality of segmental lements, means for loosely retaining said segmental elements assembled together, and resilient means interposed between said tubular body and said rings for urging the latter outwardly.

3. A piston for deep well pumps comprising a tubular body having a plurality of piston rings surrounding the same, and means associated with said rings for imparting a slight rotary motion thereto upon reciprocation of the piston.

4. A piston for deep well pumps comprising a tubular body having a plurality'of metal piston rings surrounding the same, and an annular member mounted on said tubular body in frictional engagement with said rings, and having a plurality of grooves therein inclined to the axis of the piston to impart rotation to the rings upon axial reciprocation of the piston.

5.;A piston for deep well pumps comprising a tubular body'having a plurality of metal piston rings surrounding the same, a plurality of spacing rings interposed between adjacent piston rings, and an annular member mounted on said tubular body in frictional engagement with aid rings, and having a plurality of grooves therein inclined to the axis of the piston to impart rotation to the rings upon axial reciprocation of the piston. p r j 6. A piston for deep well pumps comprising a tubular body having a plurality of metal piston rings surrounding the same, each piston ring being formed of a plurality of segmental elements, means for loosely retaining said segmental elements assembled together, and an annular member mounted on said tubular body in-frictional engagement with said rings; and having a plurality of grooves therein inclinedto the axis of the piston to impart rotation to the rings upon axial reciprocation of thepiston.

7. A piston for deep well-pumps comprising a tubular body, an annular member rotatably sur-' rounding the body at one end thereof, abutment means for preventing axial displacement of said member from the tubular body, a plurality of metal piston rings on said tubular body, annular spacing elements positioned on said tubular body between said rings, a detachable abutment at the other end of said tubular body for retaining said rings and spacing elements against axial displacement on said tubular body, said piston rings each being formed of a plurality of segmental elements, and means on said spacing elements for cooperating with the segmental elements to retain the latter assembled together.

8. A piston for deep well pumps comprising a tubular body, an annular member rotatably surrounding the body at one end thereof, abutment means for preventing axial displacement of said member from the tubular body, a plurality of metal piston rings on said tubular body, annular spacing elements positioned on said tubular body between said rings, and a detachable abutment at the other end of said tubular body for retaining said rings and spacing elements against axial displacement on said tubular body, said annular member being mounted on said tubular body in frictional engagement with said rings, and having a plurality of grooves therein inclined to the axis of the piston to impart rotation to the rings upon axial reciprocation of the piston.

9. A piston for deep well pumps Comprising a tubular body, an annular member rotatably surrounding the body at one end thereof, abutment means for preventing axial displacement of said member from the tubular body, a plurality of metal piston rings on said tubular body, annular spacing elements positioned on said tubular body between said rings, a detachable abutment at the other end of said tubular body for retaining said rings and spacing elements against axial displacement on said tubular body, said piston rings each being formed of a plurality of segmental elements, and means on said spacing elements for cooperating with the segmental elements to retain the latter assembled together, said annular member being mounted on said tubular body in frictional engagement with said rings, and having a plurality of grooves therein inclined to the axis of the piston to impart rotation to the rings upon axial reciprocation of the piston.

10. A piston for deep well pumps comprising a tubular body, an annular member rotatably surrounding the body at one end thereof, abutment means for preventing axial displacement of said member from the tubular body, a plurality of metal piston rings on said tubular body, annular spacing elements positioned on said tubular body between said rings, a detachable abutment at the other end of said tubular body for retaining said rings and spacing elements against axial displacement on said tubular body, said piston rings each being formed of a plurality of segmental elements, and means on said spacing elements and on said rotatable annular member and said detachable abutment for cooperating with the piston ring elements to retain the latter assembled together.

11. A piston for deep well pumps comprising a tubular body, an annular member rotatably surrounding the body at one end thereof, abutment means for preventing axial displacement of said member from the tubular body, a plurality of metal piston rings on said tubular body, annular spacing elements positioned on said tubular body between said rings, a detachable abutment at the other end of said tubular body for retaining said rings and spacing elements against axial displacement on said tubular body, said piston rings each being formed of a plurality of segmental elements, means on said spacing elements and on said rotatable annular member and said detachable abutment for cooperating with the piston ring elements to retain the latter assembled together, saidannular member being mountedon said tubular body in frictional engagement with said rings, and having a plurality of grooves therein inclined to the axis of the piston to impart rotation to the rings upon axial reciprocation of the piston.

12. A piston for deep well pumps comprising a tubular body, an annular member rotatably surrounding the body at one end thereof, abutment means for preventing axial displacement of said member from the tubular body, a plurality of metal piston rings on said tubular body, annular spacing elements positioned on said tubular body between said rings, a detachable abutment at the other end of said tubular body for retaining said rings and spacing elements against axial displacement on said tubular body, said piston rings each being formed of a plurality of segmental elements, axially extending flanges on the ends of said piston rings adjacent the inner periphery thereof, and axially extending flanges on the spacing elements, annular member and detachable abutment adjacent the outer periphery thereof overlapping the flanges on the piston rings to retain the elements of the piston rings assembled together.

13. A piston for deep well pumps comprising a tubular body, an annular member rotatably surrounding the body at one end thereof, abutment means for preventing axial displacement of said member from the tubular body, a plurality of metal piston rings on said tubular body, annular spacing elements positioned on said tubular body between said rings, a detachable abutment at the other end of said tubular body for retaining said rings and spacing elements against axial displacement on said tubular body, said piston rings each being formed of a plurality of segmental elements, axially extending flanges on the ends of said piston rings adjacent the inner periphery thereof, and axially extending flanges on the spacing elements, annular member and detachable abutment adjacent the outer periphery thereof overlapping the flanges on the piston rings to retain the elements of the piston rings assembled together, said annular member being mounted on said tubular body in frictional engagement with said rings, and having a plurality of grooves therein inclined to the axis of the piston to impart rotation to the rings upon axial reciprocation of the piston.

14. A piston for deep well pumps comprising a tubular body, an annular member rotatably surrounding the body at one end thereof, abutment means for preventing axial displacement of said member from the tubular body, a plurality of metal piston rings on said tubular body, annular spacing elements positioned on said tubular body between said rings, a detachable abutment at the other end of said tubular body for retaining said rings and spacing elements against axial displacement on said tubular body, said piston rings each being formed of a plurality of segmental elements, means on said spacing elements for cooperating with the piston ring elements to retain the latter assembled together, and resilient means interposed between said tubular body and said rings for urging the latter outwardly.

10 latter outwardly.

elements, axially extending fianges'on the ends of said piston rings adjacent the inner periphery thereof, axially extending flanges on the spacing elements, annular member and detachable abutment, adjacent the outer periphery thereof overlapping the flanges 0n the piston rings to retain the elements of the piston rings assembled together,and resilient means interposed between said tubular. body and said rings for urging the JESSE M. PRA'IT. 

